Supernova remnant. X-ray image of supernova remnant (SNR) G21.5-0.9. An SNR is the expanding shell of material ejected by a supernova,a huge explosion that occurs when a massive star runs out of nuclear fuel. It emits X-rays as it becomes heated during ejection. The source seen at lower right (green) is thought to be a foreground binary system containing two stars held in orbit around each other. The G21.5-0.9 data are a calibration source for X-ray observations made by the European Space Agency XMM-Newton satellite,launched in 1999 | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / ESA |
Taille de l’image : | 821 px × 827 px |
Model Release : | Non requis |
Property Release : | Non requis |
Restrictions : |
|